如何使用循环在数组的开头插入值

Question

我想使用循环在同一个数组中显示偶数和奇数。我怎么能在 PHP 中做到这一点？我想先插入偶数，然后再插入奇数。

我试图存储$i数组的偶数索引和数组的奇数，$j但我现在怎么能先添加偶数然后奇数。

输出应该在单个数组中

 2,4,6,8,1,3,5,7,9

Answer 1

首先运行偶数循环并将其存储在数组中，并以相同的方式运行奇数循环$array = array();for($i = 1; $i < 9; $i++){&nbsp;if($i%2 == 0)&nbsp;{&nbsp; &nbsp;$array[] = $i;&nbsp;}}for($i = 1; $i < 9; $i++){&nbsp;if($i%2 == 1)&nbsp;{&nbsp; &nbsp;$array[] = $i;&nbsp;}}print_r($array);

Answer 2

另一种循环 1 次的算法也取决于模运算符<?php$array = [1,2,3,4,5,6,7,8,9];$odd = [];$even = [];foreach($array as $num){&nbsp; &nbsp; if ($num % 2){&nbsp; &nbsp; &nbsp; &nbsp; $odd[] = $num;&nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; $even[] = $num;&nbsp; &nbsp; }}$finalArray = array_merge($even, $odd);var_dump($finalArray);这输出array(9) {&nbsp; [0]=>&nbsp; int(2)&nbsp; [1]=>&nbsp; int(4)&nbsp; [2]=>&nbsp; int(6)&nbsp; [3]=>&nbsp; int(8)&nbsp; [4]=>&nbsp; int(1)&nbsp; [5]=>&nbsp; int(3)&nbsp; [6]=>&nbsp; int(5)&nbsp; [7]=>&nbsp; int(7)&nbsp; [8]=>&nbsp; int(9)}现场演示https://3v4l.org/k7CmG